Magneto-electric machine



A. P. YOUNG.

A MAGNETO ELECTRIC MACHINE.

APPLICATION m50 Nov.15, 1920. n 1,427,671. Patented Aug. 29, 1922.

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ms ATTORNEY.

INVEN TOR;

ARTH by titti'hgiji PATENT Qfifl.

ARTHUR PRIMROSE YOUNG, OF KENILWORTH, ENGLAND.

MAGNETO-ELECTRIC MACHINE.

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'Application led November 15, 1920. Serial No. 424,062.

To all 'whom it may concern:

Be it known that I, ARTHUR PRiMRosii YOUNG, a citizen ofGreat Britain, residing at Dovedale, Kenilworth, in the county of Viarwickshire, England, have invented certain new and useful Improvements in Magneto-Electric. Machines, of which the following is a. specification.

This invention relates to magneto electric machines such as are commonly used in combination with internal combustion engines to eifect ignition within the cylinders and relates more particularly to devices which are known as impulse starters employed to accelerate the armature of a magneto to produce arspark in one of the cylinders of the engine when the latter is being rotated at a low speed, for example when being turned by hand at starting.

In such a device the magneto is usually driven fromthe engine through a coupling,`

part of which forms the resilient connection between the driving and the driven member and is so arranged that the initial movement of the engine shaft stresses this connection up to a certain point and after a predetermined movement the connection is free so that the magneto armature is again rotated -or given an impulse so as to produce a spark in the cylinder7 the timing of the spark being arranged so that it occurs when the piston of the cylinder is in an appropriate position. i

Impulse starters of this type usually consist of a member rigidly secured to theengine shaft and resiliently connected by means of a spring to a member secured to 'the rotor shaft of the magneto this second member being provided with a catch adapted to engage with a lined stop or projection so that when the engine shaft is turnedv the magneto rotor is prevented fromturning with it, and the motion of the engine shaft stores up energy in the resilient connection. Means are provided whereby the catch is freed from the stop after the engine vshaft has been rotated through a predetermined angle so that the energy stored up is utilrzed to give the rotor armature quick rotating ymotionV or impulse sufficient to produce a spark. u

The present invention consists in an 1mproved starter of this type.

In the accompanying drawings which illustrate one form. of my invention, Fig. 1 is an end elevation of a cover plate rigidly secured to the magneto casing. end elevation of the member which is secured to the rotor shaft of the magneto. Fig. 3 is a similar view of the member which is secured to the engine shaft. Fig. 4 shows the'members illustrated in Figs. 2 and 3 in their respective positions and Fig. 5 is a sectional elevation of the complete impulse starter essembled.

In carrying this invention into effect as illustrated I provide a disc member 1 rigidly secured to the shaft of the magneto. This member is provided at itsl periphery with a longitudinal flange 2 having one or more radial apertures yin which hardened steel plungers 3 are adaptedto slide. Surrounding this member is a second cup shaped member 4 which is resiliently secured to the disc member 1 by means of a strong spiral spring 5. The steel plungers 3 project through the apertures in the flange 2 and are held in contact with the cup shaped surfaces formed on the inner side of the cup member by means of leaf springs 6. Mounted on pivots secured to the innery ends of these plungers are biased pawls 7. These pawls are adapted to engage a stop or projection 8 formed on a cover plate 9 rigidly Vsecured to the frame of the magneto. The

cup shaped member 4- is rigidly secured lto the engine shaft and power is transmitted from the driving shaft to the magneto shaft Athrough the spring 5 connecting the cup and disc members. The spring pressed plungers 3 are adapted normally to tit into two slight recesses `9 formed at the ends of cam surfaces 10 formedL on the inner side of the .flange of the member 4 so that in addition to the spring 5 there is a certain mechanical connection between the cup and disc members through these plungers. In operation, the engine or driving shaft is slowly rotated. The vmagneto shaft with the disc member attached to it will also rotate until one of the pawls 7 attached to the spring pressed plungers comes in contact with the projection 8 secured to the magneto frame. No further movement of the magneto shaft can now take place andV any further movement of the driving shaft causes the plunger 3 to ride over the cam surfaces 10 on the inner Fig. 2 is an y side of the cup member to force the spring pressed plunger inward carrying with it the pawl which is attached to its inner end, and at the same time Winding up the spring 5 forming the resilient connectionbetiveen the coupling disc members. The profile of the cam 10 is so shaped that after a certain movement, the plungers Will be forced inward to such an extent-thatthe paWl is clear of the projection 8 on the cover plate secured to the magneto frame, at which moment the disc member 1 and magneto shaft will be free to rotate which it does through a limited angle owing to the return of the spring 5 to its normal position. The armature of the niagneto thus receives a sharp impulse which is su'liicient to produce a spari; of strong intensity and is generally sufiicient to start the engine. Assuming that it vis sufficient to start the engine the speed rapidly increases and the centrifugal action is sufficient to throw the heavy ends of the paWls 7 outwards thereby Withdraivingthe outer ends, so that they no longer come in contact With the projection 8. Means would be provided to prevent the heavy ends of the paWls being thrown out too far from the centre in which case they might come in Contact with the stops, as for example the pins 11 secured to the vpaivls and engaging the inner side of the flange'Q.

It Will be obvious that in place of the. flange Q 'being circular it may be mutilated 0r cut away and only those portions left through .which the plungers 3 pass in which case the ends of the springs G Would be held in place by means of pins secured to the disc member instead of entering slots formed in the flange 2 as illustrated.

Vhat I claim as'new and desire to secure by Letters Patent of the United States is l. An impulse starter for an internal coinbustion engine in which the charge is ig- ;nited by a spark produced by a magneto electric machine comprising `in combination a disc member rigidly secured to the shaft of the magneto, a cup shaped member sur rounding the disc member and resiliently secured thereto, said cup shaped member being also rigidly secured to the engine shaft, and third member rigidly secured to the frame ofthe magneto, a pivoted pawl carried by the disc member, a stop onthe third member engaged thereby and 'means for automatically withdrawing the paWl in a radial direction from engagement with the stop when the engine shaft has been rotated through a predetermined angle.

2. An impulse starter for an internal combustion engine in which the charge is ignited by a spar-li produced by afmagneto electric :machine comprising in combination a dise 'memberrigidly secured to the shaft lof the magneto, a cup shaped member surrounding the disc member @and resiliently secured rigir ly secured to the engine shaft, and a third member rigidly secured to the frame of lie magneto, a pivoted pawl carried by the disc member, a stop on the third member engaged thereby a spring pressed plunger rigidiy secured to said paivl and means for causing said plunger o move radially 1nfliereto, said cup-shaped member being also wird as the engine shaft is rotated.

3. Ain impulse starter for an interna-l combustion engine in which the chaige is ignited by a spark produced by a magneto electric machine .coifnprising` in combination a disc member rigidly secured to the shaft of the magneto, a cup shaped member surrounding the disc member and resiliently secured thereto, said cup shaped member being also rigidly secured to the engine shaft and a third member krigidly secured to the frame of the magneto, a pivoted paivl carried by the disc member, a stop on the tliirdmembei' engaged thereby, a spring pressed plunger upon which the said paivl is pivoted, a cam surface formed on the cup shaped member adapted to engage said spring pressed plunger and means for causing said cam surface to move the plunger inward so as to disengage the parvl from the stop.

Il, 1n an impulse starter the combination of a spring pressed plunger mounted 0n a rotatable member a pivoted pin carried by said plunger, a paivl mounted on said Din, a rigid stop adapted to be engaged by said payvl and means for moving the plunger against the action of the spring to release 'the said paul from said stop.

lin impulse starter for an internal combustion engine in which the charge is ignited by sparlr produced by a magneto electric machine comprising in combination a disc member rigidly secured lto the shaft of the magneto, cup shaped member surrounding the disc member rigidly secured to the engine shaft a spring connectedat one end to the disc member and at the other end to the cup shaped member, a third member rigidly secured to the frame of the magneto, a radially movable plunger carried by the disc member, a spring co-ogerating with said plunger, a piroted pin rigidly secured to said plunger, a paivl mounted on said pivoted pin, a stop carried by the third member cooperating with the pawl and a cam Aformed on the cup shaped member co-operating with the plunger.

6. An impulse starter for an internal combustion en gine in which the charge is ignited bya sparlr produced by a magneto electric machine comprising in combination a disc member rigidly secured to the shaft of the magneto, a cupshaped member surrounding secured to the frame of the magneto, tivo (1o-operating with the pawls, and cams radially movable plungers carried by the formed on the cup shaped member c0-operdisc member' and arranged diametroally opating with the plungers. l(

posite each other, springs cooperating with In Witness whereof, I have hereunto set said plungers, pivoted pins rigidly secured my hand this 14th day of October 1920.

to said plungers, pawls mounted on Said pivoted pins, stops carried by the third member ARTHUR PRIMROSE YOUNG. 

